Exclusive Tide Clock - Indian River Inlet, Delaware - This 10 3/4" clock depicts the beautiful new Indian River Inlet Bridge at night. Available only through Treasurequestshoppe.biz - A Photographic Art Clock by BeachClocks - clock face photo by Elton Murray. Based on a lunar day of 24 hours and 50 minutes, our tide clocks operate on a semidiurnal tide basis (most commonly associated with the U.S. East Coast), which have two high tides and two low tides of about the same height each tidal lunar day. Our tide clocks count down the number of hours until the next high semidiurnal or low tide. Unlike some tide clocks, our tide clocks include the extra tick mark in the 6th hour needed to approximate a 25 hour tidal lunar day. Because there are many variable factors that can affect the tides including location and weather, our tide clocks are not described, promoted or intended to be used as “accurate instruments”. Rather, once properly set these decorative tide clocks can approximate some useful information about the tides and they can provide a reasonable guide to local tidal changes - especially on the U.S. East Coast. The Tide clocks come with a built in hanger for mounting. BeachClocks are Designed, Printed and Assembled in the USA